U.S. patent number 3,982,383 [Application Number 05/523,509] was granted by the patent office on 1976-09-28 for harvesting platform with a floating cutter bar.
This patent grant is currently assigned to Deere & Company. Invention is credited to Roger Eugene Mott.
United States Patent |
3,982,383 |
Mott |
September 28, 1976 |
**Please see images for:
( Reexamination Certificate ) ** |
Harvesting platform with a floating cutter bar
Abstract
A self-propelled combine has a forwardly extending, vertically
adjustable crop-feeding housing and a transversely elongated,
cutter bar type harvesting platform mounted on the forward end of
the housing. The platform includes a transversely elongated frame
with a transverse flexible cutter bar disposed along the leading
edge of the platform floor. The cutter bar is mounted on the
platform by a plurality of transversely spaced parallel type
linkages that permit independent vertical adjustment of different
areas of the cutter bar so that the cutter bar is free to follow
the contour of the ground. A wobble type drive mechanism is mounted
on one end of the cutter bar and floats therewith, and a sheet-like
spring member spans the width of the platform and has its rearward
end attached to the platform floor and its forward end connected to
the cutter bar, the spring member deflecting downwardly as the
cutter bar swings downwardly to partially counterbalance the weight
of the cutter bar, the spring member also sealing the area between
the floor and the cutter bar. Structure is also provided for
adjusting the cutter bar in a fore and aft direction relative to
the floor to vary the distance between the cutter bar and the
platform auger.
Inventors: |
Mott; Roger Eugene (Bettendorf,
IA) |
Assignee: |
Deere & Company (Moline,
IL)
|
Family
ID: |
24085333 |
Appl.
No.: |
05/523,509 |
Filed: |
November 13, 1974 |
Current U.S.
Class: |
56/11.6;
56/DIG.15; 56/12.7; 56/208 |
Current CPC
Class: |
A01D
34/30 (20130101); A01D 41/14 (20130101); A01D
41/142 (20130101); A01D 57/26 (20130101); Y10S
56/15 (20130101) |
Current International
Class: |
A01D
34/02 (20060101); A01D 34/02 (20060101); A01D
34/30 (20060101); A01D 34/30 (20060101); A01D
41/00 (20060101); A01D 41/00 (20060101); A01D
57/00 (20060101); A01D 41/14 (20060101); A01D
41/14 (20060101); A01D 57/26 (20060101); A01D
57/26 (20060101); A01D 57/00 (20060101); A01D
069/08 () |
Field of
Search: |
;56/15.8,312,257,181,10.4,10.2,11.6,12.7,14.3,208,221,296,DIG.10,DIG.15,14.9 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Mancene; Louis G.
Assistant Examiner: Hamilton; James D.
Claims
I claim:
1. A harvesting platform for a mobile harvesting machine
comprising: a transversely elongated platform frame having opposite
sides; a platform floor extending between the opposite sides; a
transverse flexible cutter bar assembly including a reciprocatable
sickle, extending between the opposite sides forwardly of the floor
and operative to flex vertically to a limited degree to follow the
contour of the ground; means mounting the cutter bar assembly on
the platform frame for vertical adjustment relative thereto so that
the cutter bar assembly follows the contour of the ground; a drive
mechanism having a rotary input element and a reciprocating output
element drivingly connected to the sickle, the drive mechanism
being mounted on one end of the cutter bar assembly for vertical
adjustment therewith, and a belt drive means mounted on one side of
the platform frame on the same side of the platform as the drive
mechanism and operatively connected thereto, said belt drive means
including belt tensioning means operative to provide belt tension
regardless of the vertically adjusted position of the drive
mechanism relative to the platform frame.
2. The invention defined in claim 1 wherein the means mounting the
cutter bar assembly on the platform frame includes a plurality of
transversely spaced linkages, each linkage including a generally
fore and aft push link having its rearward end pivotally connected
to the platform frame through an axially transverse pivot and its
forward end connected to the cutter bar assembly by an axially
transverse pivot, so that the cutter bar swings vertically in a
vertical arc about the rear pivots and is free to tilt to a limited
degree about the forward pivots.
3. The invention defined in claim 2 and including a transversely
elongated, resiliently flexible sheet-like spring means having its
rearward end rigidly attached to the platform floor and its forward
end connected to the cutter bar assembly, the forward end of the
spring means deflecting downwardly as the cutter bar assembly
swings downwardly to follow the contour of the ground, so that the
spring means exerts an upward force on the cutter bar assembly
partially counterbalancing the weight of the cutter bar
assembly.
4. The invention defined in claim 3 wherein the spring means
substantially spans the width of the platform and seals the gap
between the forward end of the platform floor and the cutter bar
assembly.
5. The invention defined in claim 3 wherein the means mounting the
cutter bar assembly on the platform frame includes a plurality of
generally fore and aft support members disposed below and connected
to the floor, the linkages being connected to the support members
in alternate fore and aft positions to selectively vary the fore
and aft position of the cutter bar assembly.
6. The invention defined in claim 1 and including a transversely
elongated, resiliently flexible sheet-like spring means having its
rearward end rigidly attached to the platform floor and its forward
end connected to the cutter bar assembly, the forward end of the
spring means deflecting downwardly as the cutter bar assembly
swings downwardly to follow the contour of the ground, so that the
spring means exerts an upward force on the cutter bar assembly
partially counterbalancing the weight of the cutter bar
assembly.
7. The invention defined in claim 6 wherein the spring means
substantially spans the width of the platform and seals the gap
between the forward end of the platform floor and the cutter bar
assembly.
8. The invention defined in claim 6 wherein the means mounting the
cutter bar assembly on the platform frame includes a plurality of
generally fore and aft support members connected to and disposed
below the floor and a plurality of vertically adjustable linkage
means operatively connected to the support members in alternate
fore and aft positions and vertically adjustably carrying the
cutter bar assembly.
9. A harvesting platform for a mobile harvesting machine
comprising: a transversely elongated platform frame having opposite
sides; a platform floor extending between the opposite side; a
transverse flexible cutter bar assembly extending between the
opposite sides forwardly of the floor and operative to flex
vertically to a limited degree to follow the contour of the ground;
linkage means mounting the cutter bar assembly on the platform
frame for vertical adjustment relative thereto so that the cutter
bar assembly is free to follow the contour of the ground; and a
transversely elongated, resiliently flexible, sheet-like spring
means having its rearward end rigidly attached to the platform
floor and its forward end connected to the cutter bar assembly, the
forward end of the spring means deflecting downwardly as the cutter
bar simply swings downwardly to follow the contour of the ground,
so that the spring means exerts an upward force on the cutter bar
assembly partially counterbalancing the weight of the cutter bar
assembly.
10. The invention defined in claim 9 wherein the spring means
comprises a single pan like element that substantially spans the
width of the platform and seals the gap between the forward end of
the platform floor and the cutter bar assembly.
11. The invention defined in claim 10 wherein the means mounting
the cutter bar assembly on the platform frame includes a plurality
of generally fore and aft support members disposed below the floor
and linkage means operatively connected to the support members in
alternate fore and aft positions and vertically adjustably carrying
the cutter bar assembly.
12. A harvesting platform for a mobile harvesting machine
comprising: a transversely elongated platform frame having opposite
sides; a platform floor extending between the opposite sides; a
transverse flexible cutter bar assembly extending between the
opposite sides forwardly of the floor and operative to flex
vertically to a limited degree to follow the contour of the ground;
a plurality of generally fore and aft support members connected to
the frame and disposed below the floor; and linkage means
connecting the support members to the cutter bar assembly for
permitting independent vertical adjustment of different portions of
the cutter bar assembly so that the cutter bar assembly follow the
contour of the ground and including means operatively connecting
the linkage means to the support members at alternate fore and aft
positions to selectively vary the fore and aft positions of the
cutter bar assembly relative to the platform frame.
13. The invention defined in claim 12 wherein the linkage means
includes a plurality of transversely spaced linkages, each linkage
including a generally fore and aft push link having its rearward
end pivotally connected to the platform frame through an axially
transverse pivot and its forward end connected to the cutter bar
assembly by an axially transverse pivot, so that the cutter bar
swings vertically in a vertical arc about the rear pivots and is
free to tilt to a limited degree about the forward pivots.
14. A harvesting platform for a mobile harvesting machine
comprising: a transversely elongated platform frame having opposite
sides; a platform floor extending between the opposite sides; a
transverse flexible cutter bar assembly extending between opposite
sides forwardly of the floor and operative to flex vertically to a
limited degree to follow the contour of the ground; a plurality of
transversely spaced linkages operatively mounting the cutter bar
assembly on the platform frame for independent vertical adjustment
of different portions of the cutter bar relative to the platform
frame so that the cutter bar assembly is free to follow the contour
of the ground, each linkage including a generally fore and aft push
link having its rearward end pivotally connected to the platform
frame through an axially transverse pivot and its forward end
connected to the cutter bar assembly by an axially transverse pivot
and a generally fore and aft stop arm generally parallel to and
forwardly of the push link, the forward and rearward ends of each
stop arm being respectively rockably connected to the platform
frame and the cutter bar assembly for swinging about transverse
axes to form a parallel type linkage with the push links whereby
the cutter bar swings vertically in a vertical arc in a generally
horizontal condition.
15. The invention defined in claim 14 wherein each stop arm is
engageable with its associated push link to limit the upward
movement of the linkage and thereby limit the upward movement of
the cutter bar assembly.
16. The invention defined in claim 14 wherein each stop arm
includes abutment means engageable with its associated push link,
to limit the downward movement of the linkage and thereby limit the
downward movement of the cutter bar assembly.
17. The invention defined in claim 14 and including a transversely
elongated, resiliently flexible sheet-like spring means having its
rearward end rigidly attached to the platform floor and its forward
end connected to the cutter bar assembly, the forward end of the
spring means deflecting downwardly as the cutter bar assembly
swings downwardly to follow the contour of the ground, so that the
spring means exerts an upward force on the cutter bar assembly
partially counterbalancing the weight of the cutter bar assembly.
Description
BACKGROUND OF THE INVENTION
This invention relates to an improved harvesting platform having a
flexible cutter bar assembly, such as is used on a combine or the
like.
Cutter bar type platforms are conventionally carried at the front
of self-propelled harvesting machines, such as combines, and are
transversely elongated relative to the direction of travel. The
platforms are also conventionally vertically adjustable, and, when
the platform is being used to harvest such crops as soybeans or the
like, the platform is operated as close to the ground as possible.
Such platforms conventionally include a floor with a transverse
cutter bar along the leading edge of the floor. A reel is also
normally provided above the cutter bar and moves the crop toward
the cutter bar as the machine advances, the crop severed by the
cutter bar being fed to a transverse auger which converges the crop
along the floor toward the center of the platform floor for
rearward discharge.
The platform floor is normally rigid; although, it is known to
provide a flexible cutter bar assembly, which is free to flex in a
vertical direction so that the cutter bar assembly is free to
follow the contour of the ground. It is further known to mount the
flexible cutter bar assembly on the platform frame by means of a
number of transversely spaced fore and aft extending arms which are
free to swing vertically to allow independent vertical adjustment
of the different areas of the cutter bar. It is also known to
provide spring means operative between the platform frame and the
cutter bar assembly to partially counterbalance the weight of the
cutter bar assembly to reduce the weight of the cutter bar assembly
supported on the ground.
The cutter bar assembly conventionally includes a reciprocating
sickle driven by a drive mechanism on one side of the platform that
converts rotary motion to the reciprocating motion required by the
sickle. One of the problems associated with the use of such cutter
bars, of course, is the driving connection between the drive
mechanism, which is normally rigid with the platform frame, and the
sickle, which is free to flex in a vertical direction.
SUMMARY OF THE INVENTION
According to the present invention, an improved flexible cutter bar
type harvesting platform is provided for use with combines and the
like.
An important feature of the improved flexible cutter bar platform
resides in the mounting of a drive mechanism for the cutter bar
assembly directly on the cutter bar asembly so that the drive
mechanism floats up and down with the cutter bar assembly,
eliminating the necessity for a compensating mechanism between the
drive mechanism and the cutter bar assembly. Also, the drive
mechanism has a rotary input sheave driven by a belt drive mounted
on one side of the platform, and a belt-tensioning mechanism is
provided in a belt drive to compensate for the movement of the
drive mechanism.
Another feature of the invention resides in the provision of a
plurality of transversely spaced generally fore and aft linkages
pivotally connected at their rearward ends to the platform frame
and their forward ends to the cutter bar assembly, the double pivot
linkages permitting the cutter bar assembly to ride in a
substantially horizontal condition, regardless of the vertical
position of the cutter bar assembly relative to the platform frame.
More specifically, the linkages include rearward push arms,
pivotally connected to the cutter bar assembly and the platform
frame, and stop arms generally parallel to and forwardly of the
push arms and also pivotally connected to the cutter bar assembly
and swingable relative to the platform assembly, the push arms and
the stop arms forming a parallel type linkage, with the stop arms
limiting the movement of the cutter bar assembly relative to the
platform frame.
Another feature of the invention resides in the provision of a
transversely elongated, resilient, sheet-like spring element having
its rearward end connected to the forward end of the floor and its
forward end connected to the cutter bar assembly, the spring
element functioning as a seal to close the gap between the platform
and the cutter bar assembly and as a spring partly counterbalancing
the weight of the cutter bar assembly to reduce the weight of the
cutter bar assembly supported on the ground.
Still another feature of the invention resides in the provision of
means for adjusting the cutter bar assembly in a fore and aft
direction relative to the platform frame to allow the positioning
of the cutter bar assembly in its optimum position relative to the
platform auger for different types of crops and crop conditions.
Still more specifically, the cutter bar mounting linkages are
mounted on generally fore and aft support arms, which telescope in
a fore and aft direction in fore and aft support members attach to
the bottomm of the platform frame, means being provided for
attaching the support arms in alternate fore and aft positions
relative to the support members.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a left front perspective view of a harvesting platform
embodying the invention and mounted on a self-propelled combine,
only the forward portion of which is shown, the cutter bar assembly
being shown in a flexed condition such as it would be during
operation when riding over uneven terrain.
FIG. 2 is an enlarged side elevation view of the platform with the
cutter bar assembly in its uppermost position relative to the
remainder of the platform.
FIG. 3 is an enlarged section view of the rear portion of the
cutter bar assembly mounting means as viewed generally along the
line 3--3 of FIG. 2.
FIG. 4 is an enlarged side elevation view of the platform similar
to FIG. 2, but showing the cutter bar assembly in its lowermost
position relative to the platform floor.
FIG. 5 is a side elevation view similar to FIG. 4, but showing the
cutter bar assembly in an intermediate vertical position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention is embodied in a self-propelled combine having a main
separator body 10, only the forward portion of which is shown in
FIG. 1. As is conventional, the combine is mounted on a pair of
forward drive wheels 12 and has a forward, elevated operator's
station 14 and a forwardly extending vertically adjustable crop
feeding housing, that is not shown in detail. An improved cutter
bar type platform, indicated generally by the numeral 16 is mounted
on the forward end of the feeder housing for vertical adjustment
therewith. As is conventional, the harvesting platform 16 removes
the crop from the field, converges it, and delivers it rearwardly
to the crop feeding housing, which in turn delivers it to a
separating mechanism in the combine body 10.
The platform 16 includes a transversely elongated frame indicated
generally by the numeral 18. The frame 18 includes a transverse
tubular beam 20, that spans the width of the platform at a lower
rearward portion thereof, and a plurality of upright frame members
22 extending upwardly from the tubular beam 20 on the rearward side
of the platform. The platform frame also includes right and left
side walls or panels 24, 26, respectively, and divider points 28
are provided along the leading edge of the right and left side
panels 24 and 26. The platform also includes a floor 30 which spans
the width of the platform between the right and left side panels 24
and 26 immediately above and forwardly of the tubular beam 20.
A transverse crop converging auger 32 is disposed immediately above
the floor and has oppositely wound flights on its opposite ends for
moving the crop toward the center of the platform, where it is fed
rearwardly to the crop feeding housing by a plurality of feeder
fingers 33, which are mounted on the auger 32 in a wall known
manner. The platform floor includes an arcuate portion 34 generally
concentric with the auger and closely adjacent to the lower rear
portion thereof. The floor also includes a horizontal forward
portion 36 that extends tangentially forwardly from the arcuate
portion 34. An auger stripper 38 is disposed adjacent to the
rearward side of the auger at the rearward end of the floor 34 at
the junction of the floor with an upright rear wall 39 of the
platform.
A transversely extending cutter bar assembly, indicated in its
entirety by the numeral 40, spans the width of the platform between
the opposite side panels 24 and 26 forwardly of the leading edge of
the floor 30. The cutter bar assembly is of the flexible or
floating type, wherein the cutter bar is free to flex in a vertical
direction to a limited degree so that it is able to follow the
contour of the ground. Such flexible cutter bars are well known and
have been used on combine platforms when harvesting low lying
crops, such as soybeans and the like, a typical flexible cutter bar
being shown in U.S. Pat. No. 2,795,922. The cutter bar assembly 40
includes a transverse beam 42 that spans the width of the platform
and is free to flex in a vertical direction, although substantially
rigid in a fore and aft direction. A plurality of mower guards 44
that are mounted side by side on the beam 42 in a known manner, and
a transversely reciprocal sickle bar 46 is mounted for
reciprocation in the mower guards, also in a known manner.
A drive mounting bracket 48 is mounted on the left hand end of the
cutter bar beam 42 adjacent the exterior side of the left side
panel 26, the beam 42 extending through an opening in the side
panel, and a wobble type drive mechanism 50 is mounted on the
bracket 48 on the exterior side of the side panel. Wobble type
drives are well known and convert rotary input motion to
reciprocating output motion, only the exterior housing of the drive
mechanism being shown. The drive mechanism 50 includes a rotatable
input sheave 51 rotatable about a transverse axis and a
reciprocating output arm 52 that reciprocates in a transverse
direction about a vertical axis and is connected to the cutter bar
sickel 46.
A plurality of skids 54 are attached to the cutter bar beam 42 on
the underside of the mower guards 44 at transversely spaced
intervals, the skids being located at approximately three foot
intervals across the width of the platform. Thus, in a 15-foot
platform, six skids would be provided, with a skid being located at
each end of the platform. A plurality of mounting mechanisms 56
connect the cutter bar assembly 40 to the platform frame 18, the
mounting mechanism being spaced at the same intervals as the skids.
The mounting mechanisms permit independent vertical adjustment of
different areas of the cutter bar assembly as the respective skids
follow the contour of the ground. Thus, as shown in FIG. 1, one
skid could be riding on a raised portion of ground, while the
adjacent skid is riding in a depression, so that one portion of the
cutter bar within the assembly could be raised while the adjacent
portion might be in a lowered condition, giving the cutter bar a
curved or sinewous configuration, such as shown in FIG. 1. Of
course, stops are provided to limit the uppermost and lowermost
positions of the mounting mechanisms to limit the amount of flexing
of the cutter bar assembly to a degree that will not impair the
operation of the cutting mechanism, the amount of flexing also
being limited by the degree of flexibility of the cutter bar beam
42.
Since the mounting mechanisms 56 are identical, only a single
mechanism will be described in detail. Each mechanism includes a
downwardly open, fore and aft extending, general channel shaped
support member 58 having inwardly extending ledges or lips 59 on
its lower or open side, as best shown in FIG. 3. The channel shaped
member abut the underside of the flat, forward floor portion 34 and
are rigidly secured to the floor.
The mounting mechanism includes a generally fore and aft stop arm
60 that has its rearward end disposed in the channel shaped support
member 58, the rearward end being provided with a pair of Z-shaped
tabs 62 projecting from opposite sides of the stop arm and disposed
between the top of the support member and the support member lips.
The tabs maintain the rearward end of the stop arm in the channel
shaped member while permitting fore and aft sliding movement of the
stop arm relative thereto. The stop arm is also channel shaped and
open downwardly and has a pair of outwardly extending flanges 64
along its lower sides that seat against the support member lips 59
when the stop arm is in its uppermost position parallel to the
support member. The Z-shaped tabs have upper legs 66 and lower legs
68 that are parallel and inclined downwardly and rearwardly
relative to the top of the stop arm. The top of the upper leg 66
and the bottom of the lower leg 68 respectively engage the top of
the support member and the support member lips as the stop arm
swings downwardly about its rearward end to limit the downward
movment of the stop arm, the stop arm being shown in its lowermost
position in FIG. 4, with the upper and lower legs of the Z-shaped
tabs 62 engaging the respective portions of the support member.
The front end of the stop arm 60 is connected to the cutter bar
assembly by means of a transverse front pivot 70 that is carried in
a vertical bracket 72 extending upwardly from the skid 54. The
mounting mechanism 56 also includes a generally fore and aft push
link 74 that is mounted below and rearwardly of the stop arm 60
generally parallel thereto. The push link is U-shaped in cross
section and fits into the recess of the channel shaped push link 60
when the cutter bar assembly is in its uppermost position, as shown
in FIG. 2. The rearward end of the push link 74 is pivotally
connected to the rearward end of the support member 58 by means of
a transverse rear pivot 76, while the forward end of the push link
74 is pivotally connected to the cutter bar assembly by a
transverse front pivot 78 that is carried in the vertical mounting
bracket 72 rearward of the stop arm pivot 70. As is apparent, the
stop arm and the push link form a parallel type linkage, that
permits the cutter bar assembly to adjust vertically in a generally
horizontal condition. An alternate rear push link pivot is
indicated by the numeral 79 and provides a means for mounting the
mounting mechanism in an alternate fore and aft position relative
to the support member 58, thereby permitting adjustment of the
cutter bar assembly between alternate fore and aft positions
relative to the remainder of the platform to optimize the distance
between the cutter bar assembly and the platform auger 32.
A transversely elongated, resiliently flexible, sheet-like spring
element 80 spans the width of the platform and extends between the
forward level portion 36 of the floor and the cutter bar assembly
40. The rearward end of the spring element 80 is provided with an
attaching flange 82 that is attached to the forward end of the
floor by a plurality of fasteners 84 extending through the
attaching flange and bores 86 in the floor. As is apparent, an
alternate set of bores 86 are provided forwardly of the bores 86
wherein the fasteners are shown as mounted in the drawings to
provide an alternate connection point for the spring element to the
floor, to thereby accommodate the adjustment of the cutter bar
assembly into its alternate, forward position. The front end of the
spring element 80 is provided with a hook portion 88 that extends
through a transversely elongated slot 90 formed between a top
member 91 attached to and extending rearwardly from the beam 42 and
an arcuate lower member 92 attached to and extending rearwardly
from the lower side of the guards 44. As is apparent, the forward
end of the spring element is free to slide in and out of the slot
90, providing a lost motion connection between the spring element
and the cutter bar assembly to accommodate the vertical adjustment
of the cutter bar assembly relative to the platform floor. As is
also apparent, the forward end of the spring element deflects
downwardly as the cutter bar assembly adjust downwardly to follow
the contour of the ground and functions as a leaf spring to exert
an upward force on the cutter bar assembly, the force
counterbalancing part of the weight of the cutter bar assembly to
reduce the weight of the cutter bar assembly supported on the
ground via the skids 54. The spring element also functions as a
forward extension of the floor to cover the gap between the cutter
bar assembly and the floor, providing a smooth transition for the
crop material flowing over the cutter bar to the rigid portion of
the floor while preventing the loss of material between the cutter
bar assembly and the platform floor. While the spring element is
shown as a single, transversely elongated member, the element could
obviously be formed by a number of side by side members.
A pick-up type harvester reel 94 spans the width of the platform
above the cutter bar assembly in the conventional manner, the reel
being mounted on a pair of vertically adjustable, forwardly
extending arms 96 at opposite ends of the platform. The arms 96 are
adjustable in a vertical direction by means of reel lift cylinders
98 at opposite ends of the platform to vary the height of the reel,
and means are also provided for mounting the reel on the arms at
alternate fore and aft locations, to vary the fore and aft position
of the reel, it being well known construction to optimize the
location of the reel relative to the cutter bar assembly according
to the crop and crop conditions.
The wobble drive mechanism 50 is driven by a belt drive 100 on the
left side 26 of the platform, the drive 100 being partially
shielded by a shield 101. The drive 100 includes a drive sheave 102
mounted on a transverse drive shaft 104 along the rear side of the
platform, the drive shaft being driven from the combine in a
conventional fashion. A drive belt 106 is trained around the drive
sheave 102 and the input sheave 51 of the wobble drive mechanism
50, and an idler mechanism 108 is proivided to provide proper belt
tension regardless of the position of the cutter bar assembly and
the drive mechanism mounted thereon. The idler mechanism 108
includes a fixed idler 110 that engages the inside of the belt 106,
the movable idler 112 being mounted on one end of a swingable arm
114. A generally fore and aft helical compression spring 116 exerts
a rearward force on a fore and aft link 118 extending through the
spring, the forward end of the spring being anchored on a bracket
120 attached to the platform side panel 26. The forward end of the
link 118 is connected to the opposite end of the arm 114 from the
movable idler, exerting a clockwise force on the arm that biases
the idler against the back side of the belt 106.
In operation, when the platform is being operated in low lying
crops such as soybeans, the platform advances with the cutter bar
assembly 40 riding close to the ground, the skids 54 riding along
the ground. The cutter bar is sufficiently flexible that it
generally follows the contour of the ground, the mounting mechanism
56 allowing independent vertical adjustment of the different
portions of the cutter bar assembly supported by their respective
mounting mechanisms. The vertical flexing of the cutter bar is
limited by the amount of flexibility in the cutte bar beam and is
further limited by the mounting mechanism 56.
The cutter bar assembly 40 is shown in its uppermost position
relative to the remainder of the platform in FIG. 2. In the upper
position, the top of the stop arm 60 abuts the inside of the
channel shaped member 58 so that additional upward movement is
impossible. As previously described, as the cutter bar assembly
drops relative to the rest of the platform, the stop arm 60 rocks
about its rearward end until the Z-shaped tabs 62 abut the top of
the support member and the support member lips, as shown in FIG. 4,
at which time further downward movement of the stop arm 60 is
impossible. As also previously described, the spring element 80
flexes as the cutter bar assembly swings downwardly, partially
counterbalancing the weight of the cutter bar assembly.
* * * * *